[RADIOCARBON, VOL. 4, 1962, P. 57.701 CAMBRIDGE UNIVERSITY NATURAL RADIOCARBON MEASUREMENTS V H. GODWIN and E. H. WILLIS Cambridge University 4 The dates and activity measurements given below have been obtained during the year 1961, and have been made with CO2 at 3 atmospheres pressure in a proportional gas counter as described in previous contributions from this laboratory. We have maintained our policy of directing our assays largely toward particular projects under investigation in the University Sub-department of Quaternary Research. In particular we concentrated during 1961 on the dating of sequences of samples from raised bogs where pollen-zone boundaries, strati- graphic horizons and the levels of important anthropogenic effects upon the countryside are all registered. We particularly wish to acknowledge the help of R. J. F. Burleigh, Techni- cal Assistant in the Radiocarbon Dating Laboratory. SAMPLE DESCRIPTIONS BRITISH ISLES A. Coastal series, Fenland Basin Shippea Hill series, Cambridgeshire We have already described (Cambridge III) the stratigraphic sequence at Shippea Hill, Cambridgeshire (52'° 26' 10" N Lat, 0° 23' 52" E Long), where a Neolithic occupation layer was excavated from the middle of a thick peat bed underlying the brackish-water Fen Clay of the Fenland basin. To the rune dates already published we now add three more that continue the sequence to a greater depth. Samples were secured from the same peat monolith that yielded the previously published dates, and were taken so as to date important pollen zones. Q-586. Shippea Hill, 90 cm depth 6695 ± 150 Black crumbly fen peat with some sand, in the early part of Pollen Zone VIIa with 40% Alnus, 30% Tilia. Q-587. Shippea Hill, 100 cm depth 7610 ± 150 Black amorphous peat with abundant coarse sand, in the later part of Pollen Zone VI with 80% Pinus pollen. This sample falls right within the black sandy layer shown by earlier excavations (Clark, Godwin & Clifford, 1935) to correspond with the local Mesolithic occupation of the river bank. Q-588. Shippea Hill, 130 cm depth 8620 ± 160 Black crumbly peat with coarse sand and some small wood, from the mid- Radiocarbon Dating Laboratory, 5 Salisbury Villas, Station Road, Cambridge, and Uni- versity Sub-department of Quaternary Research, Botany School, Cambridge, England. 57 58 H. Godwin and E. H. Willis die or lower part of Pollen Zone VI with Ulmus and Quercus in approximately equal frequency, and close to base of the channel at this point. General comment: The three samples now dated make a consistent extension backward in time from the nine already reported (Cambridge III). Q-587 dates the Mesolithic flint industry originally described as Late Tardenoisian, but now considered as having affinities with the French Sauveterrian, itself of Epi-gravettian character. The date is a perfectly acceptable one. The two samples Q-586 and Q-587 were chosen to bracket the transition between Pollen Zones VI and VII (i.e. the Boreal/Atlantic transition). Although only 10 cm apart their ages differ by ca. 1000 yr and it may be guessed that a hiatus separates the two samples, possibly a phase of arrested peat growth or erosion such as is already known from other sites in the Late Boreal Zone VIc pollen. The date of 8620 ± 160 B.P. for Q-588 falls within the age limits of Zone VI as determined at Scaleby Moss (Cambridge I). For more detailed descrip- tion of the recent re-excavation of Shippea Hill with archaeological, palynologic and C14 results see Clark and Godwin, 1962. B. Coastal series, Northern 1 reland On the NW shore of Strangford Lough, Co. Down (54° 30' N Lat, 5° 41' W Long), is the site of Ringneill Quay where archaeological layers associated with the 25-ft raised beach have been very carefully excavated (Stephens and Collins, 1960) and where M. E. S. Morrison (1961) reported the results of pollen analysis of associated clay layers. The boulders and shingle that form the beach pass down into a sandy, shelly layer containing marine shells, bones, charcoal and flint artifacts. This archaeological layer rests upon grey "lagoon clay" at ca. + 16 ft OD, taken to represent a stage just preceding building of the beach in the later stages of the eustatic rise of ocean level. Morrison has referred the Lagoon Clay to Pollen Zone VI with a prefer- ence for Sub-zone VIc, that is the latest phase of the Boreal. Charcoal sent us in 1957 from the original excavations was unfortunately lost in processing, but in June 1961, Dr. E. H. Willis, together with Dr. A. G. Smith and Dr. A. E. P. Collins of Queen's Univ. Belfast, revisited the site and secured for C14 assay samples including those listed below. Q-632. Ringneill Quay, Co. Down, Lagoon Clay, 8.10 cm 7345 ± 150 7500 ± 150 Brackish-water clay. Comment: the two dates yielded by this sample are in fair agreement with palynologic evidence, since a number of C14 dates of the Zone VI/VII transition in western Europe fall close to 7500 B.P. The most di- rect comparison is with the peat below the Northern Irish raised beach at Ballyhalbert, where Morrison had also inferred a Zone VIc age : Q-214, 8120 + 135 (Cambridge II). This peat now lies at less than + 7.0 ft OD and as a freshwater formation might well represent an earlier stage in the raised-beach formation than the Ringneill Quay Lagoon Clay. Cambridge University Natural Radiocarbon Measurements V 59 Q-633. Ringneill Quay, Co. Down, Occupation Layer 3680 ± 120 Charcoal from the occupation layer. Coll. June 1961 by A. E. P. Collins, the original excavator. Comment : the flints afforded no decisive guide to the age of the occupation layer. On the evidence of the bone fragments it has been thought to be of Neolithic rather than Mesolithic age. The C14 age is unexpect- edly young and entirely excludes the possibility that it was an occupation of Mesolithic people. It carries the generally unacceptable implication that the uppermost 5 or 6 ft of the heavy beach gravel was deposited after 3680 B.Y. (see below). Q-635. Ringneill Quay, Co. Down, Midden shells 2660 ± 110 Shells from midden resting upon the crest of the beach. Comment: this sets a limit to the possible age of the close of beach, but other evidence (Q-373, Cushendun, 4740 ± 110, Cambridge III and Q-533, Flander's Moss, 5492 + 130, Cambridge V) suggests a date around 5000 B.P. for the end of the eustatic rise of sealevel (Godwin, 1960). C. Coastal series, SW Scotland Earlier we reported a series of determinations aiming to procure absolute dates for the formation of the "25 ft raised beach" of Northern Britain, a structure built when the decelerating eustatic rise of ocean level was for a time approximately equalled by isostatic uplift (Cambridge III). Dates then ob- tained suggested that the beach was formed between ca. 8000 and 5000 B.P. Drs. W. W. Bishop and W. G. Jardine of the Geol. Dept., Glasgow Univ. are presently re-examining the geology of the raised beach at various sites in SW Scotland. Samples Q-637 to Q-643 were collected by them during 1961 and forwarded to us with the accompanying notes on provenance. Q-637. Redkirk Point, Dumfriesshire (A) 8135 ± 150 Wood (Grid Ref. 35/302652; 54° 58' N Lat, 3° 5' W Long), cut from HIWL,tree stump in situ upon peaty bed, here 9 in. thick, now 3 to 4 ft below normal on coast of the Solway Firth. Peat overlain by ca. 12 ft of carse-type grey clay with rhizomes, mapped by Geol. Survey as the lowest (10.15 ft) raised beach. Coll. 1961 by W. W. Bishop. Comment: the date gives a lower age limit for the Carse Clays, and agrees with the samples from Ballyhalbert (Q-214, 8120 ± 135), Airth Colliery (Q-281, 8421 ± 157), Eastfield of Dunbarney (Q-421,. 8421 ± 157), and Broombarns (Q-422, 8354 ± 143) (Cambridge .I1I) . Q-638. Lochar Moss, Dumfriesshire (B) 6645 ± 120 Peat (Grid Ref. 35/056680; 54° 59' N Lat, 3° 28' W Long), taken by 3 in, auger from 6 ft to 7 ft 3 in. below surface of the large raised bog Lochar Moss near Netherlochar Woods plantation. This moss rests on the flat surface of the "Carse Clays" which are here represented by micaceous fine sands proved to a depth of 11 ft (+ 19 ft OD). Coll 1961 by W. W. Bishop. Com- rnent : whereas this date certainly gives an upper limit for the end of the 25 ft beach deposition, it is somewhat older than that for the basal wood peat sitting upon the Carse Clays at Flander's Moss, Stirlingshire (Q-533 5942 ± 130). 60 H. Godwin and E. H. Willis Q-639. Newton Stewart, Wigtownshire (C) 6159 ± 120 Wood (Grid Ref. 25/416640; 54° 57' N Lat, 4° 28' W Long) , embedded in sediments forming the right bank of the River Cree at sharp bend one mi S of Newton Stewart. Laminated silts, 8 ft thick, overlay the sample at ca. 17 ft OD and it was underlain by similar deposits. These silts are mapped as part of the 25-ft beach by the Geol. Survey but suggest still-water deposition. The height above OD lends support to the view that the sample should fall within the time of beach formation (assuming the wood is indeed contemporary with the silt : it is clearly allochthonous) . Coll. 1961 by W. G. Jardine. Comment: the date agrees with the dates already considered if accepted as representing a late stage in the beach formation.